JPS5922661Y2 - oil-filled bushing - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil-filled bushing used in an eye of an electrical device.

Oil-filled bushings used in the sunrise parts of electrical equipment such as 27S KV class transformers have a long part exposed to the atmosphere and are heavy. It may resonate in line with the dominant frequency, creating a large vibrating mechanical force, which may cause the bushing to break or the filling oil to leak.

Generally, oil-filled bushings of 275 KV class or lower are often of the center clamp type, using the center conductor as a fixing bolt between the pipe and the mounting flange.

This method has a structure in which mechanical strength is obtained by the compressive repulsion force of the spring, and there is a limit to the tensile strength of the offshore core conductor, so if the bushing resonates during a strong earthquake, a gap will occur in the gasket on the end face of the insulator tube. Oil may leak.

For this reason, if the vibration continues for a long time, gaps will repeatedly occur in the end face gasket portion of the insulator tube, and the amount of oil leakage will increase.

Furthermore, the upper insulator can become displaced due to the inchworm phenomenon.

Therefore, in order to prevent the upper pipe from slipping, conventional oil-filled bushings are provided with a slippage prevention device consisting of a slippage prevention ring and a cushion at the lower part of the upper pipe.

1 and 2 show cross-sectional views of conventional oil-filled bushings.

In the figure, an insulating part 2 is provided around the center conductor 1 and the mounting 7
Insert into the lunge 3 and pass through the gasket 7 to the lower pipe 5.
, screw the support fitting 4 into the lower end of the center conductor 1 through the gasket 6 and fix it in place, insert the upper insulator tube 8 into the upper part through the gasket 9, and open the expansion chamber 11 through the gasket 10. Put it on.

The spring 12 is placed between the holding plates 13 within the expansion chamber 11, and the spring 12 is held down by screwing in the ring nut 14.

The structure is assembled by applying the pressure of a spring 12 to the upper insulator 8, the mounting flange 3, and the lower insulator 5, and the upper end is sealed by a bellows 17.

Then, for the purpose of checking the amount of filling oil 15, an oil level gauge 16 is installed.
is installed.

Furthermore, in order to prevent the upper insulator tube 8 from shifting, a displacement prevention ring 3a of an appropriate diameter is provided on the inner diameter side of the mounting flange 3 and the upper insulator tube 8. An O-ring 18 is fitted between the two for the purpose of cushioning.

With the above configuration, even if large vibrations continue, the O-ring 18 will not be significantly displaced by the anti-slip ring 3a.
Even if the inner diameter of the retainer tube 8 hits the anti-slip ring 3a, it acts as a cushion and prevents the retainer tube 8 from cracking.

However, with this structure, there are large manufacturing errors in the inner diameter and roundness of the O-ring, which creates a gap between the O-ring and the inner diameter of the upper pipe, preventing oil leakage when the upper pipe vibrates. The drawback was that it could not be done.

The present invention was made to solve the above-mentioned drawbacks, and by providing an elastic body having an elastic modulus smaller than that of the cushion between the cushion provided on the inner periphery of the tube and the mounting flange, To provide an oil-filled bushing that can prevent oil leakage.

The figures will be explained below.

In FIG. 3, 1 to 17 are the same as the conventional one.

A cushion 19 is wound around the outer periphery of the anti-slip ring 3a and has a predetermined elasticity, and adjusts the gap between the upper insulator tube 8 and the anti-slip ring 3a to a predetermined dimension.

20 is an elastic body provided between the cushion 19 and the upper insulator tube 8 so as to be compressed with a predetermined pressure;
It has an elastic modulus smaller than 9.

Next, the effect will be explained.

In Figure 3, if large vibrations persist, the elastic body 2
Since the upper insulator tube 8 and the elastic body 20 are pressed against each other at a predetermined pressure by a repulsive force of 0, they come into sliding contact and prevent oil leakage.

According to the present invention, by providing an elastic body having an elastic modulus smaller than that of the cushion between the upper paddle tube and the cushion, the upper paddle tube and the elastic body are in pressure contact with each other, so that the upper paddle tube is moved by vibration. Even if it is misaligned, oil leakage can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional oil-filled bushing, FIG. 2 is a sectional view showing the main part of FIG. 1, and FIG. 3 is a sectional view showing the main part of an embodiment of the present invention. In the figure, 1 is the center conductor, 3 is the mounting flange, 3a is the anti-slip ring, 5 is the lower pipe, 8 is the upper pipe, 1
2 is a spring, 19 is a cushion, and 20 is an elastic body. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] One ends of the upper and lower tubes are pressed against the mounting flange via a center conductor by a spring disposed at the other end of the upper tube, and a slip prevention ring facing the inner periphery of the upper tube is provided on the mounting flange. , in which a cushion is interposed between the upper paddle tube and the slippage prevention ring,
An oil-filled bushing characterized in that an elastic body having an elastic modulus smaller than that of the cushion is provided between the upper pipe and the cushion.